What Is A Hub?

Date First Published: 10th April 2022

Article Type: Computer Terms & Definitions

Difficulty: Medium

Difficulty Level: 5/10

Learn more about what a hub is in this article.

A hub is the most basic type of network device that connects multiple devices in a network to each other and operates in the physical layer of the OSI model. Hubs are much more basic than network switches and routers as they only transmit data to connected devices, which connect through Ethernet ports, and have no routing tables, IP addresses, or connections to sources other than local computers, which basically means no internet access. Hubs are rarely used or found now. They have been replaced by network switches and routers and are mostly used to extend a network or replace a broken network switch on a temporary basis.

Hubs do not have the intelligence to find the best path for data packets to be sent. The transmission of data to multiple ports can cause congestion, since bandwidth is shared between the connected devices. When more devices are connected to the hub, less bandwidth will be allocated for each device. Hubs broadcast data to all devices on the network rather than intended recipients. As a result, a lot of unnecessary data is sent as not all computers may need to receive the data.

How Do Hubs Work?

Hubs work by exchanging data packets with every device connected to the hub. Devices connect to the hub through the Ethernet ports and each hub normally contains 4-16 ports. Whenever a data packet arrives at one of the Ethernet ports, it is then copied to the other ports in order for the other devices to access the stored information.

Speed

Older hubs only support speeds of up to 10 Mb/s. Modern hubs support speeds of up to 100 Mb/s.

Types Of Hubs

Passive hubs – These hubs collect wires coming from other devices and connect devices to each other in a star configuration. Signals are transmitted onto the network without amplifying or being regenerated.
Active hubs – These hubs amplify and regenerate the incoming electrical signals before they are transmitted in a similar way to a repeater.
Intelligent hubs – These are active hubs that have the intelligence to find the best path for data packets to be sent and they offer additional features, such as remote network management capabilities through SNMP or VLAN. In addition, they are usually stackable, meaning that one can be placed on top of another to use space more efficiently.